Preparation of textile strands comprising fibres having different characteristics



P. M. STRANG PREPARATION OF TEXTILE STRANDS COMPRISING FIBRES HAVINGDIFFERENT CHARACTERISTICS Filed Sept. 10, 1955 jizverziar MSZWW fa??? awDec. 31, 1957 United States Patent O f PREPARATION 'OF TEXTILE *S'IRANDS COMPRIS- ING FIBRES' DIFFE'REN T TERISTICS Peter-AM; ,Strang Nee ham,Ma s Application September;l; 1953; Serial No.=379695 i 9 Claim a(CL-.Skel;

This invention wrela-tes to thepreparation ofi strand-like materialsfrom textile' fibrg and more especially -to a novel method-of andapparatuszfor use in-v the prepara tion-of-textile strands whereiiifibres having different char acteristics'are combined:

The practiceof=combining-warious natural- 'fitr res, vfor instance,linen and wool, ;in-.the manufacture ofi textile materialsprobabl y goesback to a 'tiine b'effOre the beginning of 11 recorded history, andthe-faot that fa'b'rics; made from blends-of different natural fibresyhave characteristics different from fabriesmade solely-"fromom ortheother of constituent fibres is well knowne Thusdt is' com-mon toblend thevarious fibres,- eitherinthe formation-of individual spun:yarns or bywthecombination of spun yarns of different materials inaa'weaving 'process,-=forthe purpose-of obtaining in rthe completedfabric' some-definite property: suchfor example-was:wrin-klewesis'tanee, dimensional stabilityror i-durabilityporto-(secure such esthetic properties aswfeel, drape-, surfaceatexture;color efiects, etc. Gustomarilysiinvthe preparation" of a-spun yarncomprising-- fibrestahavingudifierenticharacteristics, thesediiferentrfibres aremixediirr thedesiredpercentages at an earlystageinthe=manufactureand thus a.-ra-ndorn intermingling of :thefibresoccurs:in thecrossrsection of anyqyarns spun from such'lamixture In recentyearsextensive 'textile-"studremhaveabeen made with referenceatothe--effect:ogfi stresszapplied to textile materialsythe influence of' twist-inispunryarnupen its textile strength, flexibi1-ity,=letc:; ,and's'thebehavior of blends of different (fibres .rcombined-rin-yarnl-or fabricsOne such -study made; byeMilton Piattristrepontedgin the TextileResearch "Journal; volumesflt), No. 1; published January 1950;whereiniit :is strewn mathematically that the centralfilaments; rfibresaof'ta Espum yarnrare-subjected to r greater. stram thaniareatherouter fibres :When the yarn is longitudinally stretched randizthat maximum theoretical 1strengthioftthenyarm(thatris wtossay the sumofthe; strengthstvofzitssconstituentnfibres) islaneverv attaineds Thus,fromizthea standpoint Z of ioptimum strength, each yarnzshoulditheoreticallyicompriseiagcorea(wherein the helix. angle; of"thenfibres'; orefil'amentszis 5 relatively steep), consistingtof'fibresnorsfilaments seleetefiiprimarily for high *textile strengtlr; and:arcevering of fibres :forrning helices whose {pitch is: lessasteepsthanthat of= the=:fibres forming the core. Such'iaa;coredryarnnisardesirable; not only a in 1 the interest of 1.optimum'rstrength;;hut:1also.' be.-

cause such azyarn makesait possibleatcremploy for covering materialsrfibrehaying:desirableaesthetic eharacteristics such as; highsheen,brilliant: colors;etfeehzpleasantzfeel, etc., but whichmaywbeelackingrjiria tensile estrengtht or which-maybe-aundulyr:expensiveabutewhilmbeeomespractical for usewhen:combinediiwi-thraestrong core yarn of: cheaper material.

These,advantagesaofuthe cored yarmhave lOngfibEfil'l recognized;but'nthetpreparatielr reared Marina ar quisit fin ness lexrbinyldeeaaasl dinet p a's. b eerattead d with aration o manvrrtertdifficulty; 1fieretcfor a-sue kser dayamaah y asera imes been made bywrapping the selected'covering-fibre about a preformed core, but thismethod requires that thc core first be prepared, and usually wound upona. suitable support to form a supply package, and that thiscore then bedrawn througha spindle carrying the-covering material, also previouslyformed and woundupon. a support. One undesirable--characteristic of acored yarn so made is that it has a strong tendency to kink and twistand heretofore theonly practical wayto avoid-such aresult was toapplymore-thanonecovering, with adjacent covering layers-wound inoppositedirections, all of which increases the expense of preparationof-tlie cored yarn and substantially-limits thefineness of yarnswhichrnay be prepared in this manner; Moreover, the core and coveringmaterial as-so,assembledaredistinct and independentandare-onlyunitedfrictionally, so that whenthe combinediyarn-isveXposed -totensile-or other stress the core and covering cannotailways be dependeduponvto act as a unit;

The principal object of the present invention is to provide a novelcored strand-and aflmethodiof and apparatus'for use intherpreparationiofsuchza strand (rovingot yarn), whereinthe constituent'fibresor filaments areso concatenated that the strand nearlyapproximates the theoretical in tensile strength, and whereincoveringfibres or filaments, selected to provide a strand having'the desiredexternal characteristics, encase a core consisting of fibres havingdifferent characteristicslfrom:the covering fibres buttin which :thecore and covering are so intermingied at'an intermediate Zone. that1116260136 and'covering act substantially as a unitlwhen the .strandorvyarn issubjected to applied external stress;

A further. object-isrto provide-a novel method of an apparatus for usein the preparation: of I textile vstrand material by the suspension offibres of differentchgaracteristics in a fluid medium andthespinningaofxsuch fibres while so-suspended to-forrn a strand(rovingoryarn) in which fibres of one tof -said characters predominateat the central portion of-the strand, whilefibres: of a. differentcharacter predominate at the periphery oftheyarn;

Other and further objects and advantages ofthe inventionwill bepointedout;in=therfollowing more detaileo description and :byreferencezto the accompanying i-drawings, wherein:

Fig. lis a diagrammatic vertical section, partly. broken away,illustrative of one fOIIILOf apparatus useful inthe practice, of the:present invention;

Fig. 2 is a fragmentary elevation, to verylarge scale, illustratingayarn such asis made by the practice-of the present invention;

Fig, 3 is a section onthe line -3t 3iof Fig. 2; and,

Fig. 4 is aview, generallysirnilarzto, .Fig. 1, but illustrating amodified apparatus for usein-the practice ofta modified method.

Referring to thedrawings, numeral 1 designates a receptacleof any,suitable dimensions containing a body W of liquid, usually Water, in;which aresuspended fibres or filaments F designed to @form-the outersurface of the strandto be made, and which hereafter may. be referredto, for convenience, asthe ,covereforming fibres. As here illustrated,although without limiting intent; the second receptacle 2 is arrangedWithin-ti e receptacle 1, the receptacle 2 also containing a body ofliquid, for example water, in which are suspended-the fibresorfilaments? which difier in characteristics from the-fibres E, andwhich are designed to form the core or'intetior portion ofthe strand tobe made and which,forconvenienae, may hereaftenbe referred to as thezcoreforrningfibresi The receptacle r, 1 is provided witna.downwardiy..direetfidnutlet con u t 3 h; is. join d: a v its deliveringg ndttcaa horizontalcpipe orntubeid Thfi l'QCfiPi'fi-QQeZ filSQahifiSQfldownwardly directed conduit which terminates at the point 6, inconcentric relation to the pipe 4. Thus fluid discharged from thereceptacle 2 through the outlet member 5 is delivered as a solid streamat the axial portion of the tube 4, while fluid delivered from conduit 3forms an annular stream coaxial with said solid stream.

The tube or pipe 4 is of any desired length and at 15 joins a coaxial,rotary tube or pipe 7 provided with a pulley 8 designated toreceive abelt (not shown), whereby the pipe 7 may be rotated about its horizontalaxis rela tively to the stationary pipe 4. No details of the forsupporting the pipes 4 and 7 are here shown, nor is any attempt made toshow the requisite leal-z-tight connection between the pipes 4and 7,these features being well within the province of a skilled mechanic andbeing of a non-inventive nature. The rotary pipe section 7 terminates atthe point 9 and near its terminal is preferably provided with dischargeapertures 10 through which the fluid contents of the pipe may bedelivered radially. Any suitable means, not here shown, may be providedfor receiving water so discharged. As an example, but without limitingintent, the fluid head in the receptacles 1 and 2 may be so maintainedas to provide a velocity of flow in pipes 4 and 7 of the order from twoto ten feet per second, and good results have been obtained by the useof pipes 4 and 7 having an internal diameter of approximately /8 inch.

In the operation of this apparatus and assuming that receptacles 1 and 2contain the desired head of water (it being understood that this headwill be maintained so that the water level in each receptacle willremain constant), and assuming that the respective receptacles have beensupplied with discrete fibrous elements F and F respectively, andassuming that pipe 7 is being rotated at a constant speed, water willflow from the two receptacles 1 and 2 into the pipe 4, the water fromthe receptacle 2 entering the pipe 4 at the point 6 as above noted atthe axial portion of the pipe 4.

In accordance with a principle more fully set forth in a copendingapplication for Letters Patent Serial No. 305,208, filed August 19,1952, by Lawrence M. Keeler, now U. S. Patent No. 2,698,972, for Methodof Assembling Fibres Hydraulically, the fibres F and P which enter thepipe 4 at the region 13, and which at this time may individually be wavyor curly, tend gradually to approach the axis of the pipe 4 as thestream of water flows along said pipe from left to right, as viewed inFig. 1, and ultimately and before they reach the point and, as shown atthe region 14 of the pipe, become individually substantially straightand located near the axis of thepipe. Since the fibres F are initiallydelivered near the axis of the pipe 4, these fibres tend to becomealigned near the axis of the pipe sooner than the fibres F which aredelivered into the peripheral portion of the pipe 4 and thus in theregion 14 of the pipe 4 the straightened fibres F lie close to the axisof the pipe while the cover-forming fibres F form a more or lessdistinct annular layer surrounding the fibres F3. However, it should benoted that because the fibres are suspended in a flowing stream andbecause the fibres are neither absolutely uniform in size or length orin initial degree of curl, there is no absolute line of demarcationbetween the fibres F which form the core and the fibres F which form thecovering. As the stream of water with the suspended fibres passes thepoint 15 and into the rotating portion 7 of the pipe, the stream ofwater begins to rotate, first slowly and then more rapidly by reason ofthe friction between the stream and the inner surface of the pipe (asmore fully pointed out in the copending application for Letters PatentSerial No. 370,099, filed by Peter M. Strang July 24, 1953, now U. S.Patent No. 2,700,866, for Method of Concatenating Fibrous Elements),thereby causing the fibres F and P which have become substantiallystraight and parallel, to become twisted about each other or spun sothat as they approach the delivery end 9 of the pipe they form a rovingor yarn sufficiently self-sustaining so that it may be wound to form thepackage P, this package preferably being formed upon a core 12 as thepackage is rotated by the driven friction drum 11. Since, when thefibres enter the rotating portion 7 of the pipe, the core-forming fibresF are nearer the axis of the stream than are the cover-forming fibres F,the twisting or spinning action of the rotating body of water forms ayarn having a core C (Fig. 2) which is predominantly of the fibres F anda covering K which is predominantly of the fibres F. However, for thereason above noted, some of the core-forming fibres will trail into thecover portion during the spinning operation while some of the coveringfibres will be caught into the core portion, and thus the core andcovering are interlocked in an intermediate zone between the core properand the covering proper, so that core and covering form a unitarystructure in which the core and covering contribute to resist theeffects of externally applied stresses. Thus there is formed a yarnhaving a core of any desired type of fibre, for example fibre which ishighly resistant to tensile stress, and a covering comprising anyselected type of fibre, for example a fibre which imparts a fineappearance to the completed strand or yarn. It may be noted that byvarying the head of water in the receptacles 1 and 2 the relativevelocities of the streams passing through the delivery member 3 and thedelivery member 5 may be varied and thus, or by varying theconcentration of fibre in the two receptacles, the relative amounts ofcore and covering fibres in a completed strand may be varied. It is alsoobvious that by changing the velocity of the rotating pipe 7 the twistsper inch in the completed strand may be varied at will.

While, as above noted, it is very desirable, under most circumstances,that the core and covering be firmly united as by the intercalation offibres constituting the core and covering at the intermediate portion ofthe strand, the present invention, in its broader aspects, is applicableto the formation of a strand wherein the core is preformed, so that itsconstituent fibres and filaments do not intermingle to any appreciableextent with the fibres or filaments which form the covering. Apparatusfor use in making such strands is illustrated diagrammatically in Fig.4, wherein the numeral 21 designates a receptacle similar to thereceptacle 1 above described and which is designed to contain a body Wof water or other liquid in which the covering fibres F are suspended.This receptacle 21 has a delivery conduit 23, leading into the receivingend of a horizontal stationary pipe 24 (similar to the pipe 4 of Fig. 1)and which terminates in coaxial relation to a rotating pipe 7 similar tothat previously described. In this arrangement, the second receptacle25, which also contains a body of liquid, is arranged to one side of thereceptacle 21 and has an outlet or delivery portion 27 which merges withdelivery conduit 23 of the receptacle 21 in coaxial relation with pipe24, so that liquid flowing from the receptacle 25 enters the deliveryportion 27 of conduit 23 and merges at 28 with the liquid flowing fromreceptacle 21. As illustrated, a rotary support 29 carries a mass M ofcore strand material G which may be a synthetic filament, without twist,if desired, or which may be of spun yarn. This strand material G isdrawn off from the package or mass M and passes around a guide pulley 30and then extends through the delivery member 27 and into the pipe 24 incoaxial relation to the latter, and thence extends axially through therotary pipe 7 and is eventually wound to form a yarn package. At theregion B of the pipe 24, the fibres F (from the receptacle 21) enter thepipe 24 and tend to move toward the axis of the pipe and thus toward theportion G of the strand G which is at the axis of the pipe 24. Graduallythese fibres become straight as they move to the right along the pipe24. and as they enter the rotating pipe 7, these fibres are graduallytwisted about the strand G so as to form a cover for the latter.However, it should be noted that because the discrete fibres F arefreely suspended in the liquid and are not su te l' Qr afihzt ihfi iuntil. heate s-subhea in -'the as asfltha otat 'quisl, they ahw ittl sean anply w stina o nusfz oameteo s-strand; .h r e covered strand sulting.fl'fifihihik-RWFQQQA. r hszpresent method is substantially devoid ofany tendency to twist or ,:flificfingirommost covered yarns-rmade inccordance with custornary rmethods,andemherein a single covering ply isemployed.

While-as-l:tereinabevedescribed; and "as illustratedg the yarn or strandresulting from'the praetiee of thp present inventiomhasbut-a-single--coveringlayer, it is ;manife st that byesimplemodificationof-theapparatus hereindi sclosed (wherebymore thantworeceptacles containing fibres of diiferent kinds would be employed), alldelivering into the same pipe in coaxial relation, it would becomepossible to make a strand having a core of one material, and two or morecovering layers, each of ,a difierent material, but all firmly joinedtogether.

While certain desirable methods of procedure have herein been describedby way of example, and while apparatus for use in the practice of suchmethods has been illustrated, it is to be understood that the inventionis broadly inclusive of any and all modifications of apparatus and/ormethod steps, and any differences in sequence of method steps which areequivalent to the method or apparatus disclosed and claimed.

I claim:

1. That method of forming a textile strand having a core consistingpredominantly of fibrous elements which have certain characteristics,and a covering consisting predominantly of fibrous elements having othercharacteristics, said method comprising disposing the core-formingelements at the axis of a cylindrical stream of flowing liquid, causingthe cover-forming fibrous elements, while suspended in said stream, toapproach the axially located core-forming elements from all sides whilearranging themselves substantially parallel to the axis of the stream,and rotating a portion of the stream about its own axis thereby to twinethe cover-forming elements about the core-forming elements.

2. That method of forming a textile strand according to claim 1, whereinthe core-forming fibrous elements are first suspended in a body ofliquid and then the latter is delivered into said cylindrical stream atthe axis of the latter while moving in the direction of flow of thelatter, thereby to dispose the core-forming fibrous elements closelyadjacent to the axis of the stream before they are approached by thecover-forming fibrous elements.

3. That method of forming a textile strand according to claim 1, whereinthe core-forming and cover-forming fibrous elements are first suspendedin separate bodies of liquid, and liquid from the two bodies is mingledto form said stream, the liquid from the body which carries thecore-forming elements being so guided as to form the central portion ofsaid stream, and the liquid from the body which contains thecover-forming elements being so guided as to constitute the peripheralportion of the stream.

4. That method of forming a textile strand according to claim 1, whereinthe core-forming and cover-forming fibrous elements are firstdistributed and suspended in separate bodies of liquid, respectively,the liquid from the body which carries the cover-forming elements beingdrawn off in the form of an annular stream, and the liquid from the bodywhich carries core-forming fibrous elements being drawn ofi in such away as to fill the central space within said annular stream, androtating the composite stream thereby formed so as to intertwist thecore-forming fibrous elements and to twine the coverforming elementsabout the twisted core-forming elements.

5. That method of forming a textile strand according to claim 1, whereinthe core portion of the strand is first formed by concatinating thecore-forming fibrous 6 elemen s a ormw tssl esustaini rand nd ransi a'.l esusta-mingr trand; nth

nobody. h :llql lw. l it being passed through an elongate conduit ofcircular transverse section and under a pressure head such as to producea uniform velocity of flow of from two to ten feet per second in saidconduit, the liquid from the body, in which the core-forming fibres aresuspended, forming the center of said stream and the liquid in whichfibres of another kind are suspended, forming the peripheral portion ofsaid stream, the flow of the stream through the conduit causing all ofthe suspended fibres to migrate toward the axis of the stream and toarrange themselves substantially parallel to said axis, and rotatingthat portion of the stream which is adjacent to the delivery end of theconduit, thereby to cause the fibres as they enter the rotating portionof the stream to be intertwined to form a self-sustaining strand.

7. Apparatus for use in the manufacture of composite textile strandswherein fibrous elements of at least two diverse kinds are incorporated,and wherein fibrous elements of one kind are predominant at the coreportion of the strand and fibrous elements of another kind arepredominant in the outer portion of the strand, said apparatuscomprising receptacles for holding bodies of liquid in which the severalkinds of fibres, respectively, are suspended, means for drawing offliquid from the receptacle containing the cover-forming fibrous elementsin the form of an annular stream and for drawing off liquid containingcore-forming elements and for delivering it into the center of saidannular stream thereby forming a composite stream wherein thecore-forming fibrous elements are located predominantly adjacent to theaxis of the stream and the cover-forming fibrous elements are locatedpredominantly nearer the periphery of the stream, and means for rotatinga portion of the com posite stream thereby to twine the cover-formingelements about the core-forming elements.

8. Apparatus for use in the manufacture of composite textile strandswherein fibrous elements of at least two diverse kinds are incorporated,and wherein fibrous elements of one kind are predominant at the coreportion of the strand and fibrous elements of another kind arepredominant in the outer portion of the strand, said apparatuscomprising an elongate, horizontal pipe of circular, transverse sectionhaving a terminal portion which is rotatable about its axis, means forrotating said terminal portion, a receptacle corresponding to each typeof fibre to be used, each receptacle being designed to hold a body ofliquid having suspended therein one of the several types of fibre to beemployed, and means for drawing liquid from the several receptaclessimultaneously, and for delivering it into the receiving end of saidpipe in such relation that liquid from one of the receptacles isdelivered as a solid stream substantially at the axis of the pipe, andliquid from another receptacle is delivered in an annular stream coaxialwith the solid stream, and means for rotating the rotary portion of thepipe thereby to cause the liquid therein to rotate about the axis of thepipe so as to entwine the fibrous elements to form a strand.

9. Apparatus for use in the manufacture of composite, textile strandswherein fibrous elements of at least two diverse kinds are incorporated,and wherein fibrous elements of one kind are predominant at the coreportion of the strand and fibrous elements of another kind arepredominant in the outer portion of the strand, said apparatuscomprising an elongate, substantially horizontal pipe of circular,transverse section and of the order of /8" in diameter and having aterminal portion which is rotatable about its own axis, two receptaclesfor holding liquid, said receptacles having delivery conduits which arearranged coaxially with and which open into the receiving end of thepipe, each of said receptacles containing a body of liquid, the liquidin one receptacle having suspended therein discrete fibrous elementsdesigned to form the covering of the strand, means for guiding apreformed self-sustaining core strand down through the liquid in theother receptacle and in coaxial relation with the horizontal pipe, andmeans for turning the rotary portion of the pipe thereby to wrap thesuspended fibrous elements about the core strand.

References Cited in the file of this patent UNITED STATES PATENTS

